What is the hydroxide ion concentration in a solution with a pH of 9.65?

The Concept of Hydroxide Ion Concentration Calculation from pH

Hydroxide Ion Concentration: The hydroxide ion concentration in a solution can be determined by understanding the relationship between pH, pOH, and the concentration of hydroxide ions.

Given that pH and pOH are related by the equation pH + pOH = 14 at room temperature, we can calculate the pOH of a solution with a pH of 9.65 as follows:

pOH = 14 - 9.65 = 4.35

To find the hydroxide ion concentration ([OH⁻]), we need to take the antilogarithm of the negative pOH. Mathematically, that's [OH⁻] = antilog(-pOH) = 10⁻⁴.³⁵. Therefore, the hydroxide ion concentration is approximately 4.47×10⁻⁵ M.

Understanding the concept of pH, pOH, and their relationship is crucial in determining the concentration of hydroxide ions in a solution based on its pH value.